1. Technical Field
The present invention relates to a projection optical apparatus and a projector.
2. Related Art
There has been a known projector including a light modulator that modulates light emitted from a light source in accordance with image information and a projection optical apparatus that projects the light modulated by the light modulator on a projection surface. Further, there has been a proposed projector that incorporates a projection optical apparatus including a short-throw lens and other components for allowing projection from a position close to the projection surface (see JP-A-2012-226033, for example) and a proposed projector that incorporates a projection optical apparatus that changes the direction of light outputted from a light modulator and projects the light.
The projector described in JP-A-2012-226033 includes an optical unit including a projection optical apparatus (projection lens) and a holder, an exterior enclosure, and other components.
The projection lens includes a plurality of lenses, such as a front-side lens that contributes to an increase in the divergent angle of projected image light, and a lens barrel and is configured to be capable of proximity projection. The front-side lens is disposed in a rearmost position on the optical path among the plurality of lenses and so formed that the outer dimension of the front-side lens is greater than the outer dimension of the lens barrel.
The lens barrel is provided with a flange section, and the flange section of the projection lens is fixed to the holder with screws.
Impact could undesirably be applied to a projector, for example, by rough handling of the projector when it is installed on a desktop or any other surface. In the projector described in JP-A-2012-226033, in which the projection lens includes the front-side lens and other components, the impact could undesirably break the flange section, the holder, a member close to the flange section or the holder, or any other component because the center of gravity of the projection lens is located in a position separate from the flange section.
In a projector including a projection optical apparatus that is heavier than the projection lens described in JP-A-2012-226033 and a projector including a projection lens having a center of gravity located in a position further separate from the flange section, significant breakage could undesirably occur due to an increase in load acting on the projector.